The purpose of this continuing effort is to improve the methods of quantitating the severity of acute life threatening illness and trauma. In these investigations by an interdisciplinary group of clinicians, biomathematicians and computer scientists, a comprehensive inventory of the patient's hemodynamics, respiratory and metabolic status is obtained. Together with coded data from the clinical history and physical findings a new statistical data base is created which facilitates analysis of such data. Based on designated criteria patients are classified into specific categories of life threatening illness or trauma. The major objective of this project is the development, refinement and improvement of prognostic and severity indicators based on successive determinations of patient status. Both momentary and accumulative prognostic indices are obtained. These indices provide an objective basis for priority assignment of patients to critical care units and also serve as a measure of the effectiveness of clinical management. By identifying the primary disturbances and their severity, the extensiveness of monitoring is optimized with a view to minimizing invasiveness, technical complexity, and cost of routine monitors. Quantitation of the severity of the patient's illness on admission to the critical care system as well as the ultimate survival or fatal outcome serve as measures of effectiveness of medical care. With studies based on populations of patients with comparable severity of illness or injury, within or between hospital, we would be in a position to quantitate those facilities and ingredients of professional care which are life determining.